Modular barrier systems are extremely convenient in that they permit a particular highway barrier configuration to be re-configured, which can be often when they are used on 4-lane, road-building jobs. The barrier is moved from one lane to another quickly with equipment that lifts it slightly and slides it across the road. These modular barriers are usually in the form of molded concrete, 3-feet long, with steel plates at each end and pinned together to form long sections, which are extremely heavy and difficult to dismantle and load on flatbed trucks for transport. Heavy excavation equipment with booms that can be used for lifting are typically employed to move modular highway barriers. The most common grapple system used to grasp and lift the barrier sections has been a simple chain-and-tongs grapple. However, this method is extremely inefficient and labor intensive because it requires both an equipment operator and a laborer on the ground to place and release the tongs from engagement with the barriers. Also, because the tongs hang from a chain, the barrier load may swing as the boom swivels about its base; hence, the positioning of the barriers is not controllable, requiring further assistance from the laborer on the ground. Having a laborer handling the engagement and disengagement of the tongs, and aiding and positioning of the barrier sections creates safety hazards with this type of two-man operation.
In order to increase safety and reduce labor costs, there is a need for an economical system for lifting and positioning modular barrier sections by a single worker located a safe distance from the grapple and barrier sections. There is a further need for a safe grapple system which can quickly engage, lift, place and disengage barrier sections with speed and accuracy. Hence, it is an object of the present invention to fulfill the needs described above with an economical lift device which is safe and easy to operate, especially when lifting heavy loads such as modular highway barriers.